The first catalytic enantioselective Friedel–Crafts alkylation of indoles with α,β-unsaturated trifluoromethyl ketones has been accomplished. The reaction was achieved in the presence of the Dy(OTf)3/Pybox complex, producing the desired products in high yields (up to 99%) with good enantioselectivities (up to 86% ee). The absolute stereochemistry of the resulting adducts was determined by X-ray analysis.The first catalytic enantioselective Friedel–Crafts alkylation of indoles with α,β-unsaturated trifluoromethyl ketones has been accomplished using the Dy(OTf)3/Pybox complex.

Pinostrobin (5-hydroxy-7-methoxyflavanone) obtained in relatively large amounts from fingerroot (Boesenbergia pandurata) was converted to its C-6 and C-8 prenylated derivatives. The Mitsunobu reaction, europium(III)-catalyzed Claisen–Cope rearrangement, and Claisen reaction coupled with cross-metathesis were used as the key steps. Using a sealed-vessel microwave reactor, the Mitsunobu and Claisen/Cope reactions occurred smoothly with short reaction times and in satisfactory yields. The target compounds and five new intermediary substances showed cytotoxic activity toward SK-BR-3, MCF-7, PC-3, and Colo-320DM human tumor cell lines, and all of them had significantly lower IC50 (μM) values than pinostrobin.Pinostrobin (1) was converted to its prenylated or allylated derivatives (2–8) using a microwave reactor. All resulting compounds showed cytotoxic activity toward a panel of human tumor cell lines with significantly lower IC50 (μM) values than compound 1.